Piston



Nov. 27, 1928. 7 1,693,584

l. A. WEAVER PISTON Filed June 9, 1927 TNT ease F E E o IRA A. WEAVER, OF SPRINGFIELD, ILLINOIS.

PISTON.

Application filed June 9,

My invention concerns betterments in internal-combustion engines, whereby to improve the lubrication thereof, one aim of the invention being to so construct the pistons of the engine that the excess oil tending to pass'upwardly by their piston-rings will be automatically discharged back into crank-case before ithas an opportunity to cause harmful effects, such as the fouling of the spark plugs, etc.

A further purpose of the invention is to maintain the crank-case at a very slight pressure above atmospheric to prevent the entrance of any substantial amount of road dust into it through the breather-tube, thereby V keeping the supply of lubricating oil in bet ter' condition for efiective use.

To enable those skilled in this art to have a full and complete understanding of the in vention, in the accompanying drawing forming a part of this specification, 1 have illustrated a present desirable embodiment of the invention, the same reference characters bein used in the several views for like parts.

11 this drawing c Figure 1 is a central vertical section through the piston;

Figure 2 is a horizontal section on line 22 of Figure 1 and Figure 3 is a section through one of the piston-rings, on line 83 of Figure 2.

7 By reference to the drawing, it will be observed that the upper portion or head part 11 of the piston 12 has three piston-ring grooves 13, 14 and 15 accommodating the corresponding number of piston-rings 16, 17 and 18 of special construction and forming, in connection with the floating blocks or guide shoes 19 rockingly mounted on opposite sides of the lower portion of the piston,

' the'subject-matter of my copending patent application Serial No. 224,805, filed October 8th, 1927.

Each such piston-ring externally snugly fits'the interior of the engine cylinder 21 and internally it has a plurality of spaced lugs or projections 22, 22 bearing against the inner circular wall of the groove in which the ring is located, such protuberances being roundedoff at the top and bottom at 23, 24, (Flgure 3) to maintain communication between the arcuate spaces between the ring and the inner piston-ring groove wall on opposite sldes of the projections.

- The top wall of the upper piston-ring groove has a hole 25 extended through it in the 1927. Serial No. 197,628.

register and communication with the circular chamber back of the associated piston-ring 16 the wall between the grooves 13 and 14 is sim larly apertured at 26 diametrically opposlte the port 25; the wall between the grooves 1 1 and 15 is likewise ported at 27 below the aperture 25; and the bottom wall of the lower groove 15 has a passage 28 therethrough below the hole 26, such port 28 having its lower end equipped with a leaf-spring valve 29, the inner end of which is riveted or otherwise fixedly fastened to the piston in any approved manner to permit the valve to open and close by flexure of the spring.

Obviously, during the intake stroke of the piston, valve 29 will be closed and there will be no interference with the gaseous explosive mixture drawn into the firing chamber above the piston.

During the compression and power or explosion strokes of the piston, a very small part of the gases under pressure enter the port 25 and traverse the tortuous divided passage around both sides of the piston behind the piston-rings forcing the contents thereof out of the discharge-port 28 into the engine crank-case, the valve 29 opening automatically under the pressure exerted on its top face.

Thus any execess lubricating oil and any contaminating or diluting ingredients, such as raw gasoline, etc, in such circuitous conduit are blown out and are thereby prevented from passing upwardly into the combustion chamber where, in the form of carbon, they would foul the spark-plugs and valves. 1 In this connection, it is well to bear in mind that such excess oil tends to travel upwardly into the firing chamber through the spaces behind the piston-rings, and it is from such compartments that it is forced outwardly downwardly.

lVith a construction of this kind adequate lubrication may be applied to the cylinder and piston without danger of pumping the oil past the piston-rings into the combustion chamber, because the excess is automatically eliminated or removed in the manner specified.

Inasmuch as there is more or less constantly a delivery of gases under pressure through the'p-iston into the engine crank-case, there is of necessity a constant flow out through the breather-tube (not shown) carrying with will be reduced to a minimum and the entrance of road dust is prevented, thus precluding its mingling with the lubricating oil to the detriment of the friction-reducing properties of the latter.

Dilution of the lubricating oil tends to ocour in greatest degree when the engine is first started and it is to be observed that my novel means for the prevention thereot' becomes operative the moment the engine starts.

Those skilled in this art will readily understand that the invention is susceptible of a variety of embodiments and that the one presented is merely by way of example only, the scope of the invention being defined i the appended claims.

I claim: 7

l. A piston for internalcombustion engines having a piston-ring; groove and a piston ring therein and means to cause a portion of the gases under pressure above the piston to pass through the space ailorded bv the piston ring-groove back of the piston-i g to blow out its contents.

2. A piston tor internill-combustion engines having a plurality of piston-ring; grooves and piston-rings therein a d means to cause a portion of the gases un pressure above the piston to pass in series through the spaces atl'ordcd by the piston-ring grooves back of their piston-rings to blow out their contents.

3. A piston for internal-combustion engines having a piston-ring groove and a piston-ring therein and means to cause a portion of the gases under pressure above the piston to enter the space afforded by said groove back of its piston-ring at one pointand to leave such space at a point remote therefrom whereby to blow out the contents of such space.

i. A piston tor internal-combustion engineshaving a piston-ring groove and pisllOlldlllf therein and means to cause a portion of the gases und-r pressure above the piston to enter the space afforded by said groov back of its piston-ring at one point and to leave such space at a point remote therefrom wherel'iy toblow out the contents of such spacein combination with valve means to close said passage during theintalz -strohe of the piston. f

A piston for internal-coinbustion en- -incs having a plurality of piston-ring; grooves, piston-rings therein. and means to cause portion of the gases under pressure above the piston to pass in series through the spaces afforr ed by the piston-r ng grooves back of their piston-rings to blowout their contents, in combination with valve mess to close such conduit during theintalre stroke ot the piston.

In witness whereof I have hereunto set my hand.

me A. weaves; 

